Cutaneous T-cell lymphoma (CTCL) constitutes a malignant proliferation of T-lymphocytes that initially involves the skin, but later progresses to involve lymph nodes, blood, and other visceral organs. Diagnosis of early cutaneous disease as well as occult extra-cutaneous involvement remains difficult due to the limitations of sensitivity and specificity of current diagnostic techniques. Recently the investigators have succeeded in molecularly diagnosing CTCL by cloning the T-cell antigen receptor beta chain (TCR-B) gene rearrangement from malignant T-cells and generating patient-specific oligonucleotide probes which are capable of detecting this disease through polymerase chain reaction (PCR) amplification. The investigators intend to utilize this technique to: (1) Detect the presence of minimal residual disease; (2) demonstrate the earliest presence of the malignant clone in the skin; (3) determine the earliest onset of systemic (extracutaneous) involvement. They anticipate that the results of these experiments will elucidate the natural history of CTCL in individual patients, contribute to an understanding of the origin and progression of CTCL, and provide new probes for molecular diagnosis, therapeutic monitoring, and in-situ hybridization. Furthermore, they expect that the ability to clone TCR-B gene rearrangements rapidly will lay the foundation for new therapeutic approaches aimed at the immunomodulation of pathogenic T-cell clones in human T-cell malignancies.